Unusual extractor fan wiring?

[kwazemowdoe]

Yes another extractor fan thread, but I have checked all previous posts and none seem to match my circumstances...

I'm in the process of replacing a timed extractor fan in my bathroom with a newer model.

The bathroom has a swtiched fuse outside above the door, a pull cord switch inside, a light, and the fan.

Upon removing the old timed fan I was suprised to see so many wires. There are two cables running to the fan, and each cable is 3-core (blue,yellow,red) and bare earth. So eight wire all together. These were wired into a choccy block on the old fan but there wasn't much in the way of a wiring diagram on the old fan to say what was what. I wrote this info down as best I could and then promptly lost the note. oops

After I removed the fan I insulated the end of both of the cables that ran to the fan. I found that the light could still be operated via both the pull cord and the outside fused switch.

I'm now trying to fit a new timed fan. Unfortunately I don't have the instructions (yet... they were missing from the box but I have requested replacement) - but I can tell you that there are only three connections - L, N and T - I assume L and N is live and neutral and T is the switched live?

Anyway, even when I get hold of instructions I'm not sure they will help as I don't think they will explain why I have two sets of 3 core cable.

Can anyone advise how I should wire up the fan?

 

[andy]

you are right bout the L+N. the T would be a live from the light to say the light was on, and the L+N power to operate the fan after the live from the light has stopped. its strange how you have 2 3C+E cables instead on 2C+E

 

[ban-all-sheds]

Check to see if one of the 3C+E cables is always dead when the power is on and the lights are on/off. Maybe it used to be daisy chained to another fan...